This.
I think this points to the middle-ground reality: the Philippines was a wild west; it is ever-trying to modernize and become less of a wild west and less corrupt… but (in my experience) tends to only succeed in (very) small increments. Future wild-westness is not guaranteed, but reform/modernization is not progressing at breakneck speed, either.
This too. There is some challenging legal minutiae you should pay attention to, but remember not to lose sight that the overall tenor of Philippine law/policy makes it clear that they are not looking to tax foreign-sourced income (unless you're a Filipino citizen based in the Philippines). Moreover, everywhere in the world, there is a gap between what is written law and what is actually enforced; in my experience that gap is VERY wide in the Philippines.
I'll also say that when I read the law on foreigners and foreign-sourced income, it is clear to me it is written with a clear intention to guide (large, multinational) foreign corps employing foreign expats: register your foreign branch office, pay the employee properly, withhold their income tax, etc. The authors of the code are not thinking about solopreneurs/individuals managing their offshore holdcos on their laptop from their home office.
Again, I'm grateful for
@backpacker 's excellent insights/research. But the tone of his conclusion statements could easily lead readers to think that investigations and enforcement for individual foreigners is very high/unavoidable, and that doesn't match my experience nor that of my colleagues; nor do I see an epidemic of foreigner-with-foreign-corps tax cases in the news or in expat groups online.